Brake for electric motors.



No. 655,562. Patented Aug. 7, I900. C. A. LINDSTRUM.

BRAKE FOR ELECTRIC MOTORS.

(Application filed May 5, 1899.)

(No Model.)

Hll III I! IHH l Miran STATES ATENT Faro.

ILLINOIS, ASSIGN OR, BY DIRECT AND TO THE IIEWITT-LINDSTROM MOTORCOMPANY,

BRAKE FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 655,562, dated August'7, 1900.

Application filedMay 5,1899. Serial No. 715,691. N model.)

To all whom it 'may concern:

Be it known that 1, CHARLES A. LINDSTROM, a citizen of the UnitedStates, and a resident of Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements in Brakesfor Electric Motors, of which the following is a full, clear, and eX-act description. The object of my invention is to provide a simple,easily-operated, and effective brake for electric motors which operatesdirectly on the armature-shaft of the same, within the case of the same,and which is particularly adapted for use in conjunction with electricvehicles. This I accomplish by the means hereinafter described and asparticularly pointed out in the claims.

In the drawings, Figure 1 is a longitudinal central vertical sectionthrough one end of an electric motor employing my invention. Fig.

2 is a transverse section thereof, taken on dotted line 0 Fig. 1. Fig. 3is a horizontal section taken on dotted line 3 3, Fig. 2.

In the drawings, A represents the armatureshaft; 13, the cylindricalcasing within which the motor is inclosed; Z2, one of the heads of thesame, in which the armature-shaft is journaled, and O afriction-\\-'heel, which is suitably keyed to said shaft. The head Z9 ispref- 0 erably dished, so as to extend the length of the chamberinclosed by. said casing, and the flanged periphery of thefriction-wheel 0 revolves within the head. Hinged at one end to astationary block a, located between the 5 inner circumference of theflanged edges of' said head and the periphery of wheel 0, are twosegmental arms or brake-shoes d and e, the engaging or contact surfacesof which extend to suitable points on the opposite side of 0 the wheelto block a, where the upper arm is provided with a downwardly-extendingcurved lugf, the curvature of which is such that it will not engagewheel 0-, and where the lower arm 6 is provided with an outwardlybentend, which has an upwardly projecting lug g.

Lugsfandg of the braking-arms are ofsucb length that their ends passeach other and are connected by the end of a lever D, which is shorterarm of the same.

pivoted to each in a suitable manner at different points along itslength, as shown, and extends through a suitable opening E out throughthe casing, where it has connected to it, preferably near its outerextremity, a cord or rope F. In the event of this improved brake beingused in connection with an electric vehicle this rope F runs up over asheave m, then horizontally to another sheave n, and then upward to theextremity of the longer arm of a lever G of the first class, to which itis connected. This lever G is placed in the bottom of the carriageconvenient to the operators foot, and all he has to do in order tobrake'the motor is to press downward on the This causes the lever D tobe lifted, and by bringing the respective points at which it is pivotedto the mow able ends of the arms cl and e in the same horizontal planebrings said arms into braking contact with the wheel 0. When thepressure of the foot is removed from the lever G or the draft or rope Fis released, arms (1 and e are automatically drawn away from theperiphery of wheel 0 by the contraction of springs K K, connecting thesame to the case, as shown.

I prefer to make the engaging or contact surfaces of the braking-armscorrespond in width to that of the engaging face of the wheel 0; butsuch construction of these brak ing-arms both in this respect and inother respects may be changed without affecting the spirit of myinvention so long as their construction is such as to engagefriction-wheel O in substantially the manner hereinbefore described.

What I claim as new is-= 1. The combination with an armature-shaft, acase inclosing the same, and a dished head closing'one end thereof, of afriction-wheel secured to saidshaft and inclosed within thecircumference of said head, two brakingarms having their adjacent endspivoted at fixed points to the inner surface of said case at one side ofsaid wheel around which they extend in opposite directions to an extentslightly greater than one-half of the circum ference of said wheel,radially-arranged contraction-springs for normally keeping said arms outof contact with said wheel, and a suitable lever one end of whichextends through a suitable slot in the circumference of said head and ispivotally connected to the movable ends of both of said braking-arms.

2. The combination with an armature-shaft and a case inclosing the sameand motor thereon, of a f riotion-wheel keyed to said shaft Within saidcase, two segmental braking-arms having their adjacent ends pivoted tothe inner side of the head of said case and extending Within said casein opposite directions partially around said wheel, contraction-springswithin said case normally keeping said arms out of contact with saidwheel, and a suitable lever one end of which extends through a slot inthe circumference of the case and has the adjacent movable ends of saidbraking-arms pivoted thereto at different points.

3. The combination with a rotatable element of two brake -shoes, eachpivot-ally mounted at one end, the said brake-shoes inclosing the saidrotatable element, spring mechanism for normally maintaining adisengagement between the said shoes and the said rotatable element, alink having connection with each opposed free end of the brake-shoes,the connections of the said opposed ends with the link being separate,whereby upon proper actuation of the link the free ends of thebrake-shoes are caused to approach to engage the rotatable element, thesaid link having an elongation, a cap for inclosing the brake-shoes, aslotin the said cap through which the elongation passes, and actuatingmeans for operating the said link to cause the operation of the brake.

M. I. FRIEL, FRANK D. THOMASON.

